Script Loader: Remove importmap polyfill.

The polyfill was added in [57492], but all browsers supported by WordPress already support import maps.

This not only disables the polyfill, but completely removes it as it was only added recently and there is no usage outside of core.

Props swissspidy, desrosj, luisherranz, gziolo.
Fixes #60970.

git-svn-id: https://develop.svn.wordpress.org/trunk@58952 602fd350-edb4-49c9-b593-d223f7449a82

package.json

@@ -148,7 +148,6 @@
 		"clipboard": "2.0.11",
 		"core-js-url-browser": "3.6.4",
 		"element-closest": "^3.0.2",
-		"es-module-shims": "1.8.2",
 		"formdata-polyfill": "4.0.10",
 		"hoverintent": "2.2.1",
 		"imagesloaded": "5.0.0",

src/wp-includes/class-wp-script-modules.php

@@ -236,20 +236,6 @@ public function print_script_module_preloads() {
 	public function print_import_map() {
 		$import_map = $this->get_import_map();
 		if ( ! empty( $import_map['imports'] ) ) {
-			global $wp_scripts;
-			if ( isset( $wp_scripts ) ) {
-				wp_print_inline_script_tag(
-					wp_get_script_polyfill(
-						$wp_scripts,
-						array(
-							'HTMLScriptElement.supports && HTMLScriptElement.supports("importmap")' => 'wp-polyfill-importmap',
-						)
-					),
-					array(
-						'id' => 'wp-load-polyfill-importmap',
-					)
-				);
-			}
 			wp_print_inline_script_tag(
 				wp_json_encode( $import_map, JSON_HEX_TAG | JSON_HEX_AMP ),
 				array(

src/wp-includes/script-loader.php

@@ -96,7 +96,6 @@ function wp_default_packages_vendor( $scripts ) {
 		'lodash',
 		'wp-polyfill-fetch',
 		'wp-polyfill-formdata',
-		'wp-polyfill-importmap',
 		'wp-polyfill-node-contains',
 		'wp-polyfill-url',
 		'wp-polyfill-dom-rect',
@@ -122,7 +121,6 @@ function wp_default_packages_vendor( $scripts ) {
 		'wp-polyfill-object-fit'      => '2.3.5',
 		'wp-polyfill-inert'           => '3.1.2',
 		'wp-polyfill'                 => '3.15.0',
-		'wp-polyfill-importmap'       => '1.8.2',
 	);
 
 	foreach ( $vendor_scripts as $handle => $dependencies ) {

tests/phpunit/tests/dependencies/scripts.php

@@ -3117,9 +3117,9 @@ public function test_wp_scripts_move_to_footer( $set_up, $expected_header, $expe
 	 */
 	public function test_wp_get_script_polyfill() {
 		global $wp_scripts;
-		$script_name = 'wp-polyfill-importmap';
-		$test_script = 'HTMLScriptElement.supports && HTMLScriptElement.supports("importmap")';
-		$script_url  = 'https://example.com/wp-polyfill-importmap.js';
+		$script_name = 'tmp-polyfill-foo';
+		$test_script = 'HTMLScriptElement.supports && HTMLScriptElement.supports("foo")';
+		$script_url  = 'https://example.com/polyfill-foo.js';
 		wp_register_script( $script_name, $script_url );
 
 		$polyfill = wp_get_script_polyfill(
@@ -3133,7 +3133,7 @@ public function test_wp_get_script_polyfill() {
 
 		$expected = '( ' . $test_script . ' ) || document.write( \'<script src="' . $script_url . '"></scr\' + \'ipt>\' );';
 
-		$this->assertEquals( $expected, $polyfill );
+		$this->assertSame( $expected, $polyfill );
 	}
 
 	/**

tests/phpunit/tests/script-modules/wpScriptModules.php

@@ -700,39 +700,6 @@ public function test_wp_enqueue_script_module_registers_all_params() {
 		$this->assertStringStartsWith( '/dep.js', $import_map['dep'] );
 	}
 
-	/**
-	 * @ticket 60348
-	 *
-	 * @covers ::print_import_map_polyfill()
-	 */
-	public function test_wp_print_import_map_has_no_polyfill_when_no_modules_registered() {
-		$import_map_polyfill = get_echo( array( $this->script_modules, 'print_import_map' ) );
-
-		$this->assertSame( '', $import_map_polyfill );
-	}
-
-	/**
-	 * @ticket 60348
-	 *
-	 * @covers ::print_import_map_polyfill()
-	 */
-	public function test_wp_print_import_map_has_polyfill_when_modules_registered() {
-		$script_name = 'wp-polyfill-importmap';
-		wp_register_script( $script_name, '/wp-polyfill-importmap.js' );
-
-		$this->script_modules->enqueue( 'foo', '/foo.js', array( 'dep' ), '1.0' );
-		$this->script_modules->register( 'dep', '/dep.js' );
-		$import_map_polyfill = get_echo( array( $this->script_modules, 'print_import_map' ) );
-
-		wp_deregister_script( $script_name );
-
-		$p = new WP_HTML_Tag_Processor( $import_map_polyfill );
-		$p->next_tag( array( 'tag' => 'SCRIPT' ) );
-		$id = $p->get_attribute( 'id' );
-
-		$this->assertSame( 'wp-load-polyfill-importmap', $id );
-	}
-
 	/**
 	 * @ticket 61510
 	 */

tools/webpack/packages.js

@@ -93,7 +93,6 @@ module.exports = function (
 		'wp-polyfill-object-fit.js':
 			'objectFitPolyfill/src/objectFitPolyfill.js',
 		'wp-polyfill-inert.js': 'wicg-inert/dist/inert.js',
-		'wp-polyfill-importmap.js': 'es-module-shims/dist/es-module-shims.wasm.js',
 		'moment.js': 'moment/moment.js',
 		'regenerator-runtime.js': 'regenerator-runtime/runtime.js',
 		'react.js': 'react/umd/react.development.js',
@@ -122,7 +121,6 @@ module.exports = function (
 			'polyfill-library/polyfills/__dist/Node.prototype.contains/raw.js',
 		'wp-polyfill-dom-rect.min.js':
 			'polyfill-library/polyfills/__dist/DOMRect/raw.js',
-		'wp-polyfill-importmap.min.js': 'es-module-shims/dist/es-module-shims.wasm.js',
 	};
 
 	const phpFiles = {